Actuating device



Dec. 12, 1967 A. E. THOMPSON 3,357,265

ACTUATING DEVICE Filed Jan. 18, 1966 ,10 55 57 54 27 '1 United StatesPatent 3,357,265 ACTUATING DEVICE Alvin E. Thompson, Prospect Heights,11]., assignor to TRW Inc., Des Plaines, 11]., a corporation of OhioFiled Jan. 18, 1966, Ser. No. 521,255 2 Claims. (Cl. 7410.33)

This invention relates generally to resettable actuating devices, andmore particularly to resettable actuating devices for use withpush-button tuners on radios.

' Although this invention may find a variety of uses, it has particularutility when used in conjunction with pushbutton automobile radios, andtherefore is described in connection therewith. Many tuners ofautomobile radios are provided with a plurality of tuning slugs whichare ganged together by a common movable bar. The movable bar ispivotally connected to a rotatable shaft so that when the shaft turns ineither direction about its axis the bar is moved in substantially astraight line in one of two directions in accordance with the directionof rotation of the shaft. This causes the tuning slugs connected to therod to be moved progressively into or out of engagement with theirrespective tuning coils.

The rotatable shaft comprises a pair of rods which are secured inparallel spaced relation one to the other and these parallel rods arerotated about an axis intermediate thereof.

When one of the push buttons of an automobile radio is manuallydepressed, a cam associated with the actuating device engages one or theother of the two rods and rotates the shaft formed thereby to move thebar connected thereto and position the tuning slugs so that the radiowill receive a particular preselected radio station.

When it is desired to change the particular radio station which isselected by pressing a particular push button on the radio, the cam onthe actuating device must be released from its present position andreset to a new position in accordance with the newly selected radiostation. In automobile radios it is desirable that the cam of eachactuating device be released by tension as the push button is pulledoutwardly from its neutral position. Furthermore, it is desirable thatthe amount of tension required to release the cam of each actuatingdevice be as near as possible to the same value.

Upon manually selecting a different radio station, the movable bar ispositioned to a particular point within its movable range. This causesthe rotatable shaft to turn about its axis and be positioned to aparticular point within its rotatable range. After a different radiostation has been selected, the push button of the radio is pressedinwardly thereby applying pressure to the actuating device. This actioncauses the cam, which has been previously re leased, to engage and sensethe position of two parallel rods which make up the shaft. Additionalpressure is then applied to the actuating device to cause the cam to belocked in place in accordance with the sensed position of the engagedrods. The pressure required to lock the cam in place must besufficiently high so that the cam will not move from its locked positionduring the normal operation of the push buttons on the automobile radio.However, thepressure required to lock the cam into position must also besufiiciently low so as not to cause detuning of the tuning slugs byexcessive pressure applied to the shaft as the cam is being locked intoposition. It can be seentherefore that the pressure required to lock thecam in place falls within a relatively narrow range of pressures.

Heretofore, resettable actuating devices used with pushbutton tunershave been relatively complex requiring many components parts for theirproper operation. Furthermore, after such locking devices have beenassembled,

it may be necessary to place each individual locking device on a testbench and manually operate the device a number of times to insure thatthe release tension and the locking pressure fall within the prescribedlimits. The test operation causes the movable parts of the actuatingdevice to break in so that this required range of operating tensions andpressures is obtained. It can be appreciated that the operation ofmanual break-in is costly in two respects. Firstly, that each individualactuating device must be handled by a person who manually operates theactuating device until its locking pressure and release tension fallwithin the prescribed limits. Secondly, there is the problem ofdiscarding actuating devices which do not meet the requiredspecifications even after the break in period.

Therefore, one of the primary objects of the present invention,particularly from a manufacturing standpoint, is to provide a resettableactuating device which can be mass produced so that each individualactuating device acquires substantially the same locking pressure andeach individual locking device acquires substantially the same releasetension, thereby obviating the need for manual break in.

Another object of the present invention is to provide releasableactuating devices which have a minimum number of components and whichcomponents are easily and quickly assembled.

Still another object of the present invention is to provide a resettableactuating device for use with a pushbutton tuner of an automobile radiosuch that the push button can be pulled outwardly to release the sensingcam of the actuating device, thereby allowing manual selection of thetuner to receive a radio station, and thereafter the push button ispressed inwardly to sense the condition of the tuner and lock thesensing cam in accordance with the sensed condition.

On the drawings:

FIGURE 1 shows a side elevational view of an actuating device which isconstructed in accordance with the principles of this invention;

FIGURE 2 is a top elevational view of the actuating device of FIGURE 1and shows the condition of the actuating device when the sensing cam isreleased;

FIGURE 3 is a top elevational view of the actuating device of FIGURE 1and shows the actuating device in condition when the sensing cam islocked in position; and

FIGURE 4 is an expanded view of each component part of the actuatingdevice.

As shown on the drawings:

As seen in FIGURE 1, a portion of an actuating device 10 is positionedbetween opposing end walls 11 and 12 of a radio tuner housing. Theforward end wall 11 has an aperture 13 for receiving a main slide member14 and an extended slide member 16 of the actuating device 10, the slidemember 16 being movable in sliding relation to the slide member 14.Also, the rear wall 12 has an aperture 17 for receiving a dimensionallyreduced end portion 18 of the main slide 14. A spring 19 is positionedabout the end portion 18 of the main slide 14 and extends between therear wall 12 and a flange 21 formed integrally with the main slide 14.Therefore, the spring 18 urges the main slide 14 toward the forward wall11. Movement of the main slide 14 in the direction of the wall 11 islimited by flanges 22 and 23 which are formed as part of the main slide14 and extend beyond the opposing sides of the aperture 13 to engage thesurface of the wall 11.

An end portion 24 of the extended slide 16 is provided with serrations26 for receiving a push button. A pair of guide flanges 27 and 28 areformed integrally with the extension slide 16 and slidably engage a pairof rails 29 3 and 30 respectively which, in turn, are formed as part ofthe main slide 14.

The extension slide 16 has formed thereon a protuberance 31. As seen inFIGURES 2 and 3, the protuberance 31 consists of an arcuate portion 32which terminates in a straight portion 33 generally perpendicular to theplane of the slide 16. The straight portion 33 extends through a slot 58formed in the slide 14 (FIGURE 4). Furthermore, the straight portion 33is notched in the region indicated by reference numeral 34 for slidableengagement with a rail 36 formed on the main slide 14, as best seen inFIGURE 4. The guide flanges 27 and 28 which are in slidable contact withthe rails 29 and 39, together with the notch 34 which is in slidablecontact with the rail 36, serves to maintain the slidable relationshipbetween the main slide 14 and the extended slide 16 confined to a fixedlinear path.

A cam 37 is pivotally mounted on a pin 38 which, in turn, is fixedlysecured to the main slide 14. The cam has a pair of lobes 39 and 4%)which engage a rotatable assembly 41 when the actuating device 18 ispressed inwardly. The assembly 41 is made up of two parallel rods 42 and43 which are connected at the ends thereof. The rods 42 and 43 arerotatable about an axis which is intermediate the rods and substantiallyparallel therewith. Therefore, when the assembly 41 is rotated in onedirection, the rods 42 and 43 move in the direction indicated by thesolid arrowed line, and when the assembly 41 is rotated in the oppositedirection, the rods 42 and 43 move in the direction indicated by thedotted arrowed line.

The actuating device 10, as shown in FIGURES 1 and 2, is in the releasedcondition, and the cam 37 is free to pivot about the pin 38. However,the range of pivotal movement of the cam 37 is limited by the lobes 39and 40 which alternately engage a tab 44. The tab 44 is part of the mainslide 14 and is struck out therefrom as seen in FIGURES 2 and 3.Therefore, the cam 37 is maintained within a range of positions so thateither the lobe 39 or the lobe 40 can sense the position of the rods 42or 43 respectively, regardless of their position within the rotatablearc of the assembly 41.

A spring 46 is provided with a plurality of apertures 47, 48 and 49, asbest seen in FIGURE 4. The spring 46 is held in position over theextension slide 16 and the cam 37 by a reduced diameter portion 50 ofthe pin 38, which engages the aperture 48, and by the upper end of thetab 44 which extends through the aperture 47. Also, the tab 44 has anenlarged head portion which extends beyond the width of the aperture 47to abut against the top surface of the spring 46 as seen in FIGURES 2and 3, to thereby lock the spring 46 to the slide 14.

The aperture 49 is substantially C-shaped and thereby provides acentrally disposed gripping portion 51. When the actuating device is inthe locked position, as shown in FIGURE 3, the gripping portion 51 isurged against the cam 37. This action causes the cam 37 to be locked ina fixed position on the main slide 14. To facilitate the gripping actionof the gripping portion 51, a detent 52 is formed thereon to engage thecam 37.

The spring 46 is provided with an extended end portion 53. The end ofthe extended portion 53 is preferably arcuately shaped and crimped as at46a so as to be releasably lockable with the protuberance 31 on the mainslide 14. The spring 46 is preferably made from SAE 1095 steel and maybe approximately 0.040 inch thick. Also, it is preferable that thespring 46 has a spring temper of Rockwell C 50-52. These parametersprovide a spring which is substantially rigid yet yieldable within thesmall range necessary to lock the cam 37 in position.

When the extension slide 16 is pressed inwardly, by pressure applied tothe push button, the protuberance 31 engages the extended portion 53 ofthe spring 46. With sufficient pressure applied to the extension slide16, the protuberance will cause the spring 46 to be flexed slightlyalong the tab 44 as a fulcrum. Since the opposite end of the spring 46is held against movement by the shoulder formed on the pin 50, thegripping portion 51, namely the detent 52, is urged against the cam 37.The pressure per unit area exerted on the cam 37 is relatively highsince the entire force of the spring 46 is applied to the cam throughthe small area of the detent 52. Therefore, the cam 37 will not be movedinadvertently when engaging the rods 42 and 43 to rotate the shaft 41.

To limit the movement of the extension slide 16 in the direction of thecam 37, a pair of bosses 54 and 55 are formed on the main slide 14.Therefore, the guide flanges 27 and 28 abut against the bosses 54 and 55respectively, to stop the travel of the extension slide 16.

As seen in FIGURE 4, the rail 36 is formed by one of the side walls ofthe aperture 58. To facilitate assembly of the actuating device 10, aportion of the aperture 58 is notched so that the width of the apertureis slightly greater than the width of the straight portion 33. Thisallows the straight portion 33 to fit into the aperture 58 while theguide flanges 27 and 28 are in position on their respective rails.

When the actuating device 10 is in the locked position, as seen inFIGURE 3, the center of the protuberance 31 extends slightly beyond thearcuate portion formed near the end of the spring 46. This featuremaintains the extension slide 16 in the locked position until sufiicienttension is applied to the extension slide 16 to disengage theprotuberance 31 from the spring 46. The relationship between the amountto which the center of the protuberance extends beyond the center of thearcuate portion, which is indicated by reference numeral 56, as well asthe resiliency of the spring 46, serve to control the amount of tensionnecessary to pull the extension slide outwardly and release the cam 37.On the other hand, the relationship between the distance to which theprotuberance 31 flexes the end of the spring 46, the resiliency of thespring 46, and the configuration of the gripping portion 51, serve tocontrol the pressure necessary to move the extension slide inwardly andlock the cam 37. Therefore, the range of locking pressures and releasetensions is controlled by a minimum number of parameters, and each ofthe parameters can be maintained within a desired limit.

In summary, the present invention has provided an actuating device foruse with radio tuners. The slidable relation between the main slide 14and the extension slide 16 is maintained in a fixed path by guideflanges 27 and 28 which engage rails 29 and 30 respectively, and by thenotch 34 which engages the rail 36. The spring 46 is provided with agripping portion between the apertures 47 and 48. When the actuatingdevice is in the locked position, the protuberance 31 engages the spring46 and causes the gripping portion 51 to be urged against the cam 37 andlock the cam in place.

It can be seen therefore, that the present invention provides aresettable actuating device which has a minimum number of relativelyinexpensive component parts. Furthermore, the locking pressure andrelease tension of the actuating device are controlled by a minimum ofcontrollable parameters, thereby obviating the need for manual break in.

It will be understood that variations and modifications may be effectedwithout departing from the spirit and scope of the novel concepts ofthis invention.

What is claimed is:

1. A resettable actuating device for initially sensing a particularposition of a movable element and thereafter moving the element back tothe particular position when displaced therefrom by actuation of saidactuating device, including:

a main slide member;

- an extension slide member mounted on said main slide member forslidable movement relative thereto;

a cam pivotally connected to said main slide member for engagement withthe element .to be moved;

a substantially stiff spring having an extended portion formed at oneend thereof and further having a gripping portion, said spring beingmounted on said main slide member, said spring including a C-shapedaperture defining said gripping portion; and

a protuberance carried by said extension slide for selectively engagingthe extended portion of said spring,

whereby when said protuberance is in engagement with the extendedportion of said spring, the gripping portion of said spring is urgedagainst said cam for holding the cam in a fixed position.

2. An actuating device for a radio tuner comprising:

a first slide member;

a second slide member slidably mounted with respect to said first slidemember;

means confining the sliding movement between said first and second slidemembers to a linear path;

a cam;

a pin extending from said first slide member and pivotally mounting saidcam for limited rotary movement thereabout;

a relatively stiif spring member having one end embracing said pin andoverlying said cam;

means on said first slide member holding said spring member against saidsecond slide member and providing a fulcrum for flexing of said springmember;

means on said spring member intermediate said fulcrum and said pinproviding a pressure applying area of relatively limited extent on saidcam upon flexure of said spring member, said spring member including aC-shaped aperture defining said pressure applying area; and

releasable locking means between said spring element and said secondslide member providing for flexure of said spring element about saidfulcrum upon relative sliding movement between said first and secondslide members.

References Cited UNITED STATES PATENTS 2,820,366 1/1958 Spakman 74-10.332,930,241 3/1960 Roback 74-1033 3,086,401 4/1963 Horton 74-1033 MILTONKAUFMAN, Primary Examiner.

1. A RESETTABLE ACTUATING DEVICE FOR INITIALLY SENSING A PARTICULARPOSITION OF A MOVABLE ELEMENT AND THEREAFTER MOVING THE ELEMENT BACK TOTHE PARTICULAR POSITION WHEN DISPLACED THEREFROM BY ACTUATION OF SAIDACTUATING DEVICE, INCLUDING: A MAIN SLIDE MEMBER; AN EXTENSION SLIDEMEMBER MOUNTED ON SAID MAIN SLIDE MEMBER FOR SLIDABLE MOVEMENT RELATIVETHERETO; A CAM PIVOTALLY CONNECTED TO SAID MAIN SLIDE MEMBER FORENGAGEMENT WITH THE ELEMENT TO BE MOVED; A SUBSTANTIALLY STIFF SPRINGHAVING AN EXTENDING PORTION FORMED AT ONE END THEREOF AND FURTHER HAVINGA GRIPPING PORTION, SUCH SPRING BEING MOUNTED ON SAID MAIN SLIDE MEMBER,SAID SPRING INCLUDING A C-SHAPED APERTURE DEFINING SAID GRIPPINGPORTION; AND A PROTUBERANCE CARRIED BY SAID EXTENSION SLIDE FORSELECTIVELY ENGAGING THE EXTENDED PORTION OF SAID SPRING, WHEREBY WHENSAID PROTUBERANCE IS IN ENGAGEMENT WITH THE EXTENDED PORTION OF SAIDSPRING, THE GRIPPING PORTION OF SAID SPRING IS URGED AGAINST SAID CAMFOR HOLDING THE CAM IN A FIXED POSITION.